Condition determination apparatus and method, physical quantity information generation apparatus, and angle sensor

Abstract

An angle sensor includes a detection signal generation unit, an angle detection unit for generating a detected angle value by performing an operation using detection signals, and a condition determination apparatus. The condition determination apparatus includes an initial determination value generation unit, correction processing unit and determination unit. The initial determination value generation unit performs an operation using the detection signals to generate an initial determination value corresponding to the angle sensor condition. The correction processing unit performs correction processing on the initial determination value to generate a corrected determination value. The determination unit determines whether the angle sensor is in a normal condition on the corrected determination value basis. The initial determination value contains a variation component which varies depending on an angle to be detected. The correction processing is processing for allowing the corrected determination value to be lower in variation component than the initial determination value.

What is claimed is: 
     
       1. A condition determination apparatus for determining a condition of a physical quantity information generation apparatus for generating information having a correspondence with a predetermined physical quantity, the condition determination apparatus comprising:
 an initial determination value generation unit for generating at least one initial determination value corresponding to the condition of the physical quantity information generation apparatus based on measured sensed data output by the physical quantity information generation apparatus and received by the initial determination value generation unit; 
 a correction processing unit for performing correction processing on the at least one initial determination value to generate at least one corrected determination value; and 
 a determination unit for determining whether the physical quantity information generation apparatus is in a predetermined condition on the basis of the at least one corrected determination value, wherein 
 the sensed data contains ideal data that varies in an ideal manner and error data other than the ideal data, 
 when the physical quantity information generation apparatus is in the predetermined condition, the at least one initial determination value contains an ideal value component resulting from the ideal data and a variation component resulting from the error data, the variation component varying depending on the predetermined physical quantity, and 
 the correction processing is processing that causes the at least one corrected determination value generated when the physical quantity information generation apparatus is in the predetermined condition to be lower in variation component than the at least one initial determination value generated when the physical quantity information generation apparatus is in the predetermined condition, thus bringing the at least one corrected determination value generated when the physical quantity information generation apparatus is in the predetermined condition closer to the ideal value component of the at least one initial determination value, compared to the at least one initial determination value generated when the physical quantity information generation apparatus is in the predetermined condition. 
 
     
     
       2. The condition determination apparatus according to  claim 1 , wherein the predetermined condition is a condition in which the physical quantity information generation apparatus has not failed. 
     
     
       3. The condition determination apparatus according to  claim 1 , wherein
 the predetermined physical quantity is an angle to be detected; 
 the physical quantity information generation apparatus is an angle sensor including a detection signal generation unit and an angle detection unit, 
 the detection signal generation unit generates a plurality of detection signals each having a correspondence with the angle to be detected, 
 the angle detection unit performs an operation using the plurality of detection signals to generate a detected angle value having a correspondence with the angle to be detected, as the information having a correspondence with the predetermined physical quantity, 
 the initial determination value generation unit generates the at least one initial determination value by performing an operation using the plurality of detection signals, and 
 the correction processing unit performs the correction processing by using at least one of the plurality of detection signals. 
 
     
     
       4. The condition determination apparatus according to  claim 3 , wherein the angle to be detected is an angle that a direction of a rotating magnetic field in a reference position forms with respect to a reference direction. 
     
     
       5. The condition determination apparatus according to  claim 3 , wherein
 when the angle to be detected varies with a predetermined period, each of the plurality of detection signals contains an ideal component which varies periodically in such a manner as to trace an ideal sinusoidal curve, and an error component, 
 the ideal components of the plurality of detection signals are different in phase from each other and have a predetermined phase relationship with each other, and 
 the variation component results from the error component. 
 
     
     
       6. The condition determination apparatus according to  claim 5 , wherein
 the plurality of detection signals are a first, a second and a third detection signal of which the ideal components are different in phase from each other by 120°, 
 the at least one initial determination value is one initial determination value, 
 the at least one corrected determination value is one corrected determination value, and 
 the initial determination value generation unit generates the one initial determination value by performing an operation including determining a sum of the first to third detection signals. 
 
     
     
       7. The condition determination apparatus according to  claim 5 , wherein
 the plurality of detection signals are a first, a second, a third and a fourth detection signal, the ideal components of the first and second detection signals being different in phase from each other by 180°, the ideal components of the third and fourth detection signals being different in phase from each other by 180°, 
 the ideal components of the first and third detection signals are different in phase from each other by 90°, 
 the at least one initial determination value is a first and a second initial determination value, 
 the at least one corrected determination value is a first and a second corrected determination value, and 
 the initial determination value generation unit generates the first initial determination value by performing an operation including determining a sum of the first detection signal and the second detection signal, and generates the second initial determination value by performing an operation including determining a sum of the third detection signal and the fourth detection signal. 
 
     
     
       8. The condition determination apparatus according to  claim 5 , wherein
 the plurality of detection signals are a first, a second, a third and a fourth detection signal, the ideal components of the first and second detection signals being different in phase from each other by 180°, the ideal components of the third and fourth detection signals being different in phase from each other by 180°, 
 the ideal components of the first and third detection signals are different in phase from each other by 90°, 
 the at least one initial determination value is one initial determination value, 
 the at least one corrected determination value is one corrected determination value, and 
 the initial determination value generation unit generates the one initial determination value by performing an operation including determining a sum of a square of a difference between the first detection signal and the second detection signal and a square of a difference between the third detection signal and the fourth detection signal. 
 
     
     
       9. The condition determination apparatus according to  claim 5 , wherein
 the plurality of detection signals are a first detection signal and a second detection signal of which the ideal components are different in phase from each other by 90°, 
 the at least one initial determination value is one initial determination value, 
 the at least one corrected determination value is one corrected determination value, and 
 the initial determination value generation unit generates the one initial determination value by performing an operation including determining a sum of a square of the first detection signal and a square of the second detection signal. 
 
     
     
       10. A condition determination method for determining a condition of a physical quantity information generation apparatus for generating information having a correspondence with a predetermined physical quantity, comprising the steps of:
 generating at least one initial determination value corresponding to the condition of the physical quantity information generation apparatus based on measured sensed data output by the physical quantity information generation apparatus; 
 generating at least one corrected determination value by performing correction processing on the at least one initial determination value; and 
 determining whether the physical quantity information generation apparatus is in a predetermined condition on the basis of the at least one corrected determination value, wherein 
 the sensed data contains ideal data that varies in an ideal manner and error data other than the ideal data, 
 when the physical quantity information generation apparatus is in the predetermined condition, the at least one initial determination value contains an ideal value component resulting from the ideal data and a variation resulting from the error data, the variation component varying depending on the predetermined physical quantity, and 
 the correction processing is processing that causes the at least one corrected determination value generated when the physical quantity information generation apparatus is in the predetermined condition to be lower in variation component than the at least one initial determination value generated when the physical quantity information generation apparatus is in the predetermined condition, thus bringing the at least one corrected determination value generated when the physical quantity information generation apparatus is in the predetermined condition closer to the ideal value component of the at least one initial determination value, compared to the at least one initial determination value generated when the physical quantity information generation apparatus is in the predetermined condition. 
 
     
     
       11. The condition determination method according to  claim 10 , wherein the predetermined condition is a condition in which the physical quantity information generation apparatus has not failed. 
     
     
       12. The condition determination method according to  claim 10 , wherein
 the predetermined physical quantity is an angle to be detected, 
 the physical quantity information generation apparatus is an angle sensor including a detection signal generation unit and an angle detection unit, 
 the detection signal generation unit generates a plurality of detection signals each having a correspondence with the angle to be detected, 
 the angle detection unit performs an operation using the plurality of detection signals to generate a detected angle value having a correspondence with the angle to be detected, as the information having a correspondence with the predetermined physical quantity, 
 the at least one initial determination value is generated by an operation using the plurality of detection signals, and 
 the correction processing is performed by using at least one of the plurality of detection signals. 
 
     
     
       13. The condition determination method according to  claim 12 , wherein the angle to be detected is an angle that a direction of a rotating magnetic field in a reference position forms with respect to a reference direction. 
     
     
       14. The condition determination method according to  claim 12 , wherein
 when the angle to be detected varies with a predetermined period, each of the plurality of detection signals contains an ideal component which varies periodically in such a manner as to trace an ideal sinusoidal curve, and an error component, 
 the ideal components of the plurality of detection signals are different in phase from each other and have a predetermined phase relationship with each other, and 
 the variation component results from the error component. 
 
     
     
       15. The condition determination method according to  claim 14 , wherein
 the plurality of detection signals are a first, a second and a third detection signal of which the ideal components are different in phase from each other by 120°, 
 the at least one initial determination value is one initial determination value, 
 the at least one corrected determination value is one corrected determination value, and 
 the one initial determination value is generated by an operation including determining a sum of the first to third detection signals. 
 
     
     
       16. The condition determination method according to  claim 14 , wherein
 the plurality of detection signals are a first, a second, a third and a fourth detection signal, the ideal components of the first and second detection signals being different in phase from each other by 180°, the ideal components of the third and fourth detection signals being different in phase from each other by 180°, 
 the ideal components of the first and third detection signals are different in phase from each other by 90°, 
 the at least one initial determination value is a first and a second initial determination value, and 
 the at least one corrected determination value is a first and a second corrected determination value, 
 the first initial determination value is generated by an operation including determining a sum of the first detection signal and the second detection signal, and 
 the second initial determination value is generated by an operation including determining a sum of the third detection signal and the fourth detection signal. 
 
     
     
       17. The condition determination method according to  claim 14 , wherein
 the plurality of detection signals are a first, a second, a third and a fourth detection signal, the ideal components of the first and second detection signals being different in phase from each other by 180°, the ideal components of the third and fourth detection signals being different in phase from each other by 180°, 
 the ideal components of the first and third detection signals are different in phase from each other by 90°, 
 the at least one initial determination value is one initial determination value, 
 the at least one corrected determination value is one corrected determination value, and 
 the one initial determination value is generated by an operation including determining a sum of a square of a difference between the first detection signal and the second detection signal and a square of a difference between the third detection signal and the fourth detection signal. 
 
     
     
       18. The condition determination method according to  claim 14 , wherein
 the plurality of detection signals are a first detection signal and a second detection signal of which the ideal components are different in phase from each other by 90°, 
 the at least one initial determination value is one initial determination value, 
 the at least one corrected determination value is one corrected determination value, and 
 the one initial determination value is generated by an operation including determining a sum of a square of the first detection signal and a square of the second detection signal. 
 
     
     
       19. A physical quantity information generation apparatus comprising:
 a physical quantity information generation unit for generating information having a correspondence with a predetermined physical quantity; and 
 a condition determination apparatus, the condition determination apparatus including:
 an initial determination value generation unit for generating at least one initial determination value corresponding to a condition of the physical quantity information generation apparatus based on measured sensed data output by the physical quantity information generation apparatus and received by the initial determination value generation unit; 
 a correction processing unit for performing correction processing on the at least one initial determination value to generate at least one corrected determination value; and 
 a determination unit for determining whether the physical quantity information generation apparatus is in a predetermined condition on the basis of the at least one corrected determination value, wherein 
 
 the sensed data contains ideal data that varies in an ideal manner and error data other than the ideal data, 
 when the physical quantity information generation apparatus is in the predetermined condition, the at least one initial determination value contains an ideal value component resulting from the ideal data and a variation component resulting from the error data, the variation component varying depending on the predetermined physical quantity, and 
 the correction processing is processing that causes the at least one corrected determination value generated when the physical quantity information generation apparatus is in the predetermined condition to be lower in variation component than the at least one initial determination value generated when the physical quantity information generation apparatus is in the predetermined condition, thus bringing the at least one corrected determination value generated when the physical quantity information generation apparatus is in the predetermined condition closer to the ideal value component of the at least one initial determination value, compared to the at least one initial determination value generated when the physical quantity information generation apparatus is in the predetermined condition. 
 
     
     
       20. The physical quantity information generation apparatus according to  claim 19 , wherein the predetermined condition is a condition in which the physical quantity information generation apparatus has not failed. 
     
     
       21. An angle sensor comprising:
 a detection signal generation unit; 
 an angle detection unit; and 
 a condition determination apparatus, wherein
 the detection signal generation unit is configured to generate a plurality of detection signals each having a correspondence with an angle to be detected, 
 the angle detection unit is configured to perform an operation using the plurality of detection signals to generate a detected angle value having a correspondence with the angle to be detected, 
 the condition determination apparatus includes:
 an initial determination value generation unit for generating at least one initial determination value corresponding to a condition of the angle sensor; 
 a correction processing unit for performing correction processing on the at least one initial determination value to generate at least one corrected determination value; and 
 a determination unit for determining whether the angle sensor is in a predetermined condition on the basis of the at least one corrected determination value, 
 
 when the angle sensor is in the predetermined condition, the at least one initial determination value contains an ideal value component and a variation component, the variation component varying depending on the angle to be detected, and 
 the correction processing is processing for allowing the at least one corrected determination value generated when the angle sensor is in the predetermined condition to be lower in variation component than the at least one initial determination value generated when the angle sensor is in the predetermined condition. 
 
 
     
     
       22. The angle sensor according to  claim 21 , wherein the predetermined condition is a condition in which the angle sensor has not failed. 
     
     
       23. The angle sensor according to  claim 21 , wherein
 the initial determination value generation unit generates the at least one initial determination value by performing an operation using the plurality of detection signals, and 
 the correction processing unit performs the correction processing by using at least one of the plurality of detection signals. 
 
     
     
       24. The angle sensor according to  claim 23 , wherein
 the angle to be detected is an angle that a direction of a rotating magnetic field in a reference position forms with respect to a reference direction, 
 the detection signal generation unit includes a plurality of detection circuits for generating the plurality of detection signals, 
 each of the plurality of detection circuits includes at least one magnetic detection element for detecting the rotating magnetic field. 
 
     
     
       25. The angle sensor according to  claim 24 , wherein
 the at least one magnetic detection element includes a plurality of magnetoresistance elements connected in series, and 
 each of the plurality of magnetoresistance elements includes a magnetization pinned layer whose magnetization direction is pinned, a free layer whose magnetization direction varies depending on the direction of the rotating magnetic field, and a nonmagnetic layer located between the magnetization pinned layer and the free layer. 
 
     
     
       26. The angle sensor according to  claim 23 , wherein
 when the angle to be detected varies with a predetermined period, each of the plurality of detection signals contains an ideal component which varies periodically in such a manner as to trace an ideal sinusoidal curve, and an error component, 
 the ideal components of the plurality of detection signals are different in phase from each other and have a predetermined phase relationship with each other, and 
 the variation component results from the error component. 
 
     
     
       27. The angle sensor according to  claim 26 , wherein
 the plurality of detection signals are a first, a second and a third detection signal of which the ideal components are different in phase from each other by 120°, 
 the at least one initial determination value is one initial determination value, 
 the at least one corrected determination value is one corrected determination value, and 
 the initial determination value generation unit generates the one initial determination value by performing an operation including determining a sum of the first to third detection signals. 
 
     
     
       28. The angle sensor according to  claim 26 , wherein
 the plurality of detection signals are a first, a second, a third and a fourth detection signal, the ideal components of the first and second detection signals being different in phase from each other by 180°, the ideal components of the third and fourth detection signals being different in phase from each other by 180°, 
 the ideal components of the first and third detection signals are different in phase from each other by 90°, 
 the at least one initial determination value is a first and a second initial determination value, 
 the at least one corrected determination value is a first and a second corrected determination value, and 
 the initial determination value generation unit generates the first initial determination value by performing an operation including determining a sum of the first detection signal and the second detection signal, and generates the second initial determination value by performing an operation including determining a sum of the third detection signal and the fourth detection signal. 
 
     
     
       29. The angle sensor according to  claim 26 , wherein
 the plurality of detection signals are a first, a second, a third and a fourth detection signal, the ideal components of the first and second detection signals being different in phase from each other by 180°, the ideal components of the third and fourth detection signals being different in phase from each other by 180°, 
 the ideal components of the first and third detection signals are different in phase from each other by 90°, 
 the at least one initial determination value is one initial determination value, 
 the at least one corrected determination value is one corrected determination value, and 
 the initial determination value generation unit generates the one initial determination value by performing an operation including determining a sum of a square of a difference between the first detection signal and the second detection signal and a square of a difference between the third detection signal and the fourth detection signal. 
 
     
     
       30. The angle sensor according to  claim 26 , wherein
 the plurality of detection signals are a first detection signal and a second detection signal of which the ideal components are different in phase from each other by 90°, 
 the at least one initial determination value is one initial determination value, 
 the at least one corrected determination value is one corrected determination value, and 
 the initial determination value generation unit generates the one initial determination value by performing an operation including determining a sum of a square of the first detection signal and a square of the second detection signal.